The event features more than 400 artists — from national acts such as Mudhoney and Lord Huron to locals Dressy Bessy, A Shoreline Dream, Sauna and Hollow Talk — so it’s easy to marvel at the sheer amount of music packed into the four-day event, which begins tomorrow and continues through Sunday at 20-plus walkable venues along the South Broadway corridor.

It’s also easy to feel overwhelmed by all the unfamiliar names on the lineup. And that’s kind of the point: The UMS is all about discovery, and since your wristband or badge gets you into every venue, you can pop in and out without wasting time on something you don’t like.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

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Scenes from Day 2 of the 2012 Denver Post Underground Music Showcase. Photos by Seth A. McConnell, heyreverb.com.

And while The UMS introduced its first-ever smartphone app (available here) and will be streaming online Saturday and Sunday at heyreverb.com, we still think it’s helpful to put together a list of things you should hear.

There are too many worthy shows to include here (full disclosure: I’m on a comedy panel at 5 p.m. Saturday at Mutiny Information Cafe), but the acts below are a great place to start, and we’ve even included some record store-style “recommended if you like” picks.

Calder’s Revolvers

Morphing into a blues and soul-rock group seemed like an odd turn for the prog-inflected members of Denver’s the Archive, but Calder’s howling vocals and meaty guitars and rhythm section proved it was also a brilliant one.

RIYL: The Black Keys, Blue Cheer.

Playing: 9 p.m. Thursday at the Irish Rover.

Fat Tony

Fat Tony is arguably the No. 1 hip-hop act to check out at The UMS. This rising Houston rapper has more awards than albums, but his killer beats — courtesy of producer Tom Cruz — and literate, subversive flows make him a contender for breakout hip-hop artist of the year.

RIYL: Outkast, Das Racist.

Playing: Midnight on Thursday at Blue Ice.

Esme Patterson

Best known as one of the voices behind upbeat indie-folk act Paper Bird, Denver’s Esme Patterson crafts moody, delicate solo tunes that gather and churn like the skies before a summer thunderstorm.

Bleached

Sisters Jessica and Jennifer Clavin used to play in the Los Angeles indie-punk act Mika Miko, but their latest project finds inspiration in the bouncy, upbeat guitar rock that laid the groundwork for their former band.

RIYL: The Ramones, the Shangri-Las.

Playing: 8 p.m. Friday at the Goodwill Main Stage.

Zebroids

Only one sleeveless, bearded joke-punk band can bring an elderly man on stage to play tambourine while the band members and a dude in a zebra-head mask chuck pizzas (yes, entire pizzas) and beer into the audience between its 45-second songs. That band, of course, is Denver’s Zebroids.

RIYL: Ween, Tenacous D, chaos.

Playing: 1 a.m. Friday night at the Hi-Dive.

Somerset

If lead single “Landing Gear” is any indication, Somerset is poised to be one of Denver’s best new bands — which is unsurprising since it contains members of dearly-departed acts Everything Absent or Distorted, Bela Karoli and Rabbit Is a Sphere.

For anyone who actually reads comments… Can we please say that Zebroids are a FUN Punk band (or how about a punk band)? The word JOKE is a little misleading. They are fun. Some of their songs have funny subject matter, but to compare them to Ween and T-D? BOOOOOO!!! You wouldn’t call The Mummies or The Spits joke-punk would you?

My point is, if you like rock n roll and you like to have a good time…. SMOKIN’ ALL YOUR DOPE! ZEBROIDS!!!!!